app.onactivated = function (args) {
if (args.detail.kind === activation.ActivationKind.voiceCommand) {
// TODO: Handle relevant ActivationKinds. For example, if your app can be started by voice commands,
// this is a good place to decide whether to populate an input field or choose a different initial view.
}
else if (args.detail.kind === activation.ActivationKind.launch) {
// A Launch activation happens when the user launches your app via the tile
// or invokes a toast notification by clicking or tapping on the body.
if (args.detail.arguments) {
// TODO: If the app supports toasts, use this value from the toast payload to determine where in the app
// to take the user in response to them invoking a toast notification.
}
else if (args.detail.previousExecutionState === activation.ApplicationExecutionState.terminated) {
// TODO: This application had been suspended and was then terminated to reclaim memory.
// To create a smooth user experience, restore application state here so that it looks like the app never stopped running.
// Note: You may want to record the time when the app was last suspended and only restore state if they've returned after a short period.
}
}

if (!args.detail.prelaunchActivated) {
// TODO: If prelaunchActivated were true, it would mean the app was prelaunched in the background as an optimization.
// In that case it would be suspended shortly thereafter.
// Any long-running operations (like expensive network or disk I/O) or changes to user state which occur at launch
// should be done here (to avoid doing them in the prelaunch case).
// Alternatively, this work can be done in a resume or visibilitychanged handler.
}

if (isFirstActivation) {
// TODO: The app was activated and had not been running. Do general startup initialization here.
document.addEventListener("visibilitychange", onVisibilityChanged);
args.setPromise(WinJS.UI.processAll());
}

isFirstActivation = false;
};

function onVisibilityChanged(args) {
if (!document.hidden) {
// TODO: The app just became visible. This may be a good time to refresh the view.
}
}

app.oncheckpoint = function (args) {
// TODO: This application is about to be suspended. Save any state that needs to persist across suspensions here.
// You might use the WinJS.Application.sessionState object, which is automatically saved and restored across suspension.
// If you need to complete an asynchronous operation before your application is suspended, call args.setPromise().
};